Hysteresis

Hysteresis is dependence of a system’s response on its history. It often produces different paths during loading and unloading, so the present output cannot be determined from the present input alone.

State variable: A quantity describing a system’s condition, needed alongside external inputs to predict its future behavior. Hysteretic systems need internal state to retain information about earlier inputs.
Magnetic recording: Data storage that encodes information by controlling magnetization in a magnetic medium. Stable magnetic states preserve recorded bits after the writing field disappears.
Path dependence: Dependence of a system’s outcome on the sequence of changes used to reach its current conditions. Hysteresis is a specific form of path dependence with characteristic return-path behavior.
Elasticity: The ability of a material to deform under force and recover its shape when the force is removed. Ideal elastic response retraces its path, unlike a hysteresis loop.
Metastability: A condition in which a system remains temporarily trapped in a local energy minimum rather than reaching its global minimum. Metastable states let a system retain one response until an input crosses a threshold.
Schmitt trigger: An electronic comparator with different switching thresholds for rising and falling input signals. Its threshold hysteresis suppresses repeated switching caused by noisy inputs.
Nonlinear system: A system whose output is not proportional to its input and whose behavior can change with operating conditions. Nonlinearity can accompany hysteresis, but it does not by itself imply memory.
Viscoelasticity: Material behavior combining elastic deformation with time-dependent viscous flow. Rate-dependent loops can resemble hysteresis, though they arise partly from delayed response.
Bistability: The capacity of a system to occupy either of two stable states under the same external conditions. Two stable states can give hysteresis different outputs at the same input.
Shape-memory alloy: A metal alloy that recovers a trained shape through a reversible, temperature-driven phase transformation. Its shape recovery follows different paths during heating and cooling.

Linked from 28 pages